Composites Fabrication And Repair Carbon Fiber, Kevlar, Fiberglass and all the newest high tech composites

Fiberglass Question

Reply
Old 11-25-2013, 09:21 AM
  #1
oldbassard
Thread Starter
 
Join Date: Aug 2012
Location: Kiefer, OK
Posts: 232
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default Fiberglass Question

I posted this question in another forum, now I realize the wrong one. I am building a 60" wingspan Cessna T-50 (Sky King) The plans I have are from RCM, drawn in 1964. I am attempting to update them to newer technology.

The nacelles call to be planked with 1/8 balsa. I am new to this type of thing so I ask, if it's feasible to make the nacelle housing out of just fiberglass or should I plank it with the 1/8 balsa the cover it? I don't know if making the fiberglass only housing would cost strength or if it can be epoxied to maintain the strength it needs.


At this time I am using CAD to redraw the plans and if I can just use fiberglass for the nacelles , I need to know the approximate thickness the fiberglass should be so I can adjust size for the formers.

Any input would be helpful, thanks guys
oldbassard is offline  
Reply With Quote
Old 01-24-2014, 08:30 AM
  #2
Harley Condra
 
Join Date: Dec 2001
Location: Longwood , FL
Posts: 2,276
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default

The easiest way to make the cowling would be to follow the plans, using the materials specified. Apply a layer of 3/4 oz glass cloth and a good resin, such as Pacer Z-Poxy, or West Systems 105 resin with 207 hardener.
Sand, prime and paint.
Harley Condra is offline  
Reply With Quote
Old 01-24-2014, 10:05 AM
  #3
R8893
 
Join Date: Oct 2002
Location: Cincinnati, OH,
Posts: 867
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default

Old, the conventional wisdom is that you can't put fiberglass over an open structure. So you need to either plank the model, or build a mold and layup a fiberglass nacelle.
R8893 is offline  
Reply With Quote
Old 01-24-2014, 11:54 AM
  #4
MTK
 
Join Date: May 2004
Location: Whippany, NJ
Posts: 5,386
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default

Quote:
Originally Posted by oldbassard View Post
I posted this question in another forum, now I realize the wrong one. I am building a 60" wingspan Cessna T-50 (Sky King) The plans I have are from RCM, drawn in 1964. I am attempting to update them to newer technology.

The nacelles call to be planked with 1/8 balsa. I am new to this type of thing so I ask, if it's feasible to make the nacelle housing out of just fiberglass or should I plank it with the 1/8 balsa the cover it? I don't know if making the fiberglass only housing would cost strength or if it can be epoxied to maintain the strength it needs.


At this time I am using CAD to redraw the plans and if I can just use fiberglass for the nacelles , I need to know the approximate thickness the fiberglass should be so I can adjust size for the formers.

Any input would be helpful, thanks guys
Nacelles imply more than one engine/motor for power. A 60" span implies that the total power isn't that much, maybe 2 HP all up. Assuming two engines, a pair of .25s should be enough.

Then I suggest that you carve each nacelle in 1 pound density foam and then fiberglass each foam plug with 3 oz glass and good quality laminating epoxy (west systems, ez lam, us composites, etc etc; many choices here). Stick a, 1/8" birch ply firewall on each and hang the engine directly, No need to remove the foam unless you need space for a 4 oz tank. It will be light and functional.

If you intend to use electric motors, it's probably even simpler and you can use 2 oz glass or less. Probably 1/16" birch ply FW will be all a motor needs.

For such small power you don't need a balsa support structure on the foam. It will add a bunch of unnecessary weight (strength as well of course but it really isn't needed). If you insist, a balsa nacelle can as simple as a balsa stick skeleton with 1/16" sheeting all around, glassed with 3/4 oz glass cloth. FW may be 1/18" birch for engine or 1/16" birch for motor.
MTK is offline  
Reply With Quote
Reply


Thread Tools
Search this Thread
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off



All times are GMT -8. The time now is 04:27 PM.